After many years abroad, lawyer Thomas Borchert makes a surprise return to his hometown of Zurich. He wants to gain some distance in a trailer on his family's once stately estate, and escape the clutches of the German authorities. His former employer, the FonSonic Group, has fired him without notice due to a bribery scandal in South America. Two of Borchert's colleagues were also involved in the company's dirty dealings. But since one committed suicide and the other went into hiding, Borchert is to be branded the sole scapegoat. Although he is prepared to take responsibility for his misdeeds, he also tries to put a stop to FonSonic's activities. To do so, he wants to find evidence at a Swiss bank. But soon Borchert finds himself in new trouble.

Attorney Thomas Borchert is in custody, where he is accused of bribery and embezzlement. His former supervisor Horst Zeidler advises him to take the blame in order to then make a deal with the public prosecutor. Borchert rejects the offer. He wants to prove his innocence by legal means and is looking for a suitable defense for himself in court.

Borchert and Dominique Kuster take over the defense of the taxi driver Jrg Zollinger. Captain Furrer suspects him of the murder of a passenger, the African investigative journalist Nuka Baluba. All the evidence incriminates the uncontrolled suspect, whose testimony initially seems unreliable. Borchert is suspicious of the fact that public prosecutor Dietrich is quick to commit to Zollinger. The "lawyer without a license" suspects that Baluba's research into child labor in cobalt mines in the Congo has something to do with the murder.

When Borchert receives an anonymous message that a certain Franz Brosi is innocent, law firm boss Dominique can hardly believe it. After all, Brosi was her first client as a public defender a few years ago and had actually confessed. The two are investigating the case.

Youth psychologist Julia Egger causes a traffic accident, seriously injuring a man, and drives away in panic. Her explanation that she was deliberately forced off the road by an SUV initially sounds unconvincing to Borchert and Dominique, especially since Julia has a history of drunk driving.

What begins as a routine assignment develops into a dramatic kidnapping case involving difficult detective work for the "lawyer without a license." The title character finds himself caught between his loyalty to the family of an old friend, his relentless pursuit of the truth, and his lifelong trauma of having failed as a father himself.

Thomas Borchert stands by his conviction as an "unlicensed lawyer" never to neglect humanity when representing a client. This distinguishes him from his friend and colleague Reto, who, as a victim, witness, and legal counsel, is accused of always being "more lawyer than human being." What begins with a robbery at a pharmacy develops into an unusual case of drug crime: the trafficking of high-priced medicines.

The lawyers Borchert and Kuster are investigating a case involving a young student who has come under the crosshairs of a terrorist group.

Anton Schneider says goodbye to his wife Luise in tears and dies. Schneider was seriously ill with multiple sclerosis and was diagnosed by neurologist Dr. Hoffer medically treated. Luise Schneider reports the doctor and accuses him of incorrect treatment of her husband, which ultimately led to his death. The mandate against Dr. Hoffer takes over Dominique Kuster, who entrusts her employee Thomas Borchert with the investigation.

Borchert wants to toast three years of successful cooperation with his superior Dominique Kuster and her father, Reto Zanger. The evening is canceled because Reto Zanger is called to Geneva at short notice for a mandate. His daughter is therefore supposed to represent him at a court hearing in Zurich. The trial takes a dramatic turn when inmate Alexander Böni takes those involved as hostages.